Glucose: Sweet or bitter effects in plants-a review on current and future perspective

Sugars are metabolic substrates playing a part in modulating various processes in plants during different phases of development. Thus, modulating the sugar metabolism can have intense effects on the plant metabolism. Glucose is a soluble sugar, found throughout the plant kingdom. Apart from being a universal carbon source, glucose also operates as a signaling molecule modulating various metabolic processes in plants. From germination to senescence, wide range of processes in plants is regulated by glucose. The effect of glucose is found to be concentration dependent. Photosynthesis and its related attributes, respiration and nitrogen metabolism are influenced by glucose application. Endogenous content of glucose increases upon exposure of plant to various abiotic stresses and also when glucose is supplied exogenously. Glucose accumulation alleviates the damaging effects of stress by enhancing production of antioxidants and compounds similar to that of photosynthetic CO₂ fixation which act as an osmoticum by maintaining osmotic pressure inside the cell, pH homeostasis regulator and reduce membrane permeability during stress. Glucose interaction with various phytohormones has also been discussed in this review.